By Kent · Lock Depot Staff Writer

Pick the drop box by what goes through the slot

A drop box fails in one of two ways. Either the thing you need to drop will not fit through the slot, or the box fills up and somebody stuffs it until it jams. Both come from buying on price and guessing at size. Protex makes five wall-mount steel drop boxes that cover most small-business and property-office jobs: the SDB-100, SDB-101, SDB-106, SDB-250 and SDL-500. Here is how I would sort them.

If your deposit is cash coming out of a register at close, start with the register cash guide. This one is for keys, envelopes, rent checks and small bags.

The five, side by side

Model	Outside (H x W x D)	Inside (H x W x D)	Listing says it is for
SDB-100	6" x 4" x 10"	5-3/4" x 3-3/4" x 9-3/4"	Tips, keys, cash in a back office
SDB-101	6" x 6" x 12"	5-3/4" x 5-3/4" x 11-3/4"	Thicker envelopes, small deposit pouches
SDB-106	10" x 6" x 12"	9-3/4" x 5-3/4" x 11-3/4"	Public areas, key-copy concerns
SDB-250	9" x 12" x 5-1/2"	8-3/4" x 11-3/4" x 5-1/4"	Keys, checks, rental payments
SDL-500	13-1/2" x 15" x 11-1/4"	not on the listing	High-volume payment collection

Dimensions are height by width by depth. All five are steel, wall-mount, and described with an anti-fish design, meaning the slot is built so nobody can reach back in and pull a deposit out.

SDB-100: keys and small items, nothing thick

The smallest of the group is a 6-by-4-by-10 box. The listing calls it the cheapest way to lock up keys and small deposits behind a steel door, and says property managers buy a handful for apartment complexes. That fits. It is a good fit for a maintenance office where tenants or techs return keys, or a break room where tips go in. It is not a good fit for a business envelope: the inside is only 3-3/4 inches wide.

SDB-101: when the envelope is the problem

The SDB-101 is the same height as the SDB-100 but two inches wider and two deeper, with a wider drop slot for thicker envelopes and small deposit pouches. The listing names pharmacies, real estate offices and car dealerships for after-hours drops. If someone has ever jammed a folded envelope in your current slot, this is the step up. It has pre-drilled mounting holes.

SDB-106: the tall one

The SDB-106 is 10 inches high, which gives you more vertical room inside than the 6-inch boxes. The description calls out better lock security for a public area, where you worry about unauthorized key copies.

One thing to confirm here. The listing description says tubular key lock; the product title says dual key access. Titles and descriptions on a couple of these boxes disagree about lock type. Before you order for a spot where lock type matters, call us and we will confirm which cylinder ships on the box you are buying. I would rather say that than guess.

SDB-250: flat and wide for checks and rent

This is a different shape, not just a bigger one. At 12 inches wide and 5-1/2 deep it is shallow and broad. A business-size check envelope or a rent payment lays flat. The listing says it handles keys, checks and rental payments with more room than the SDB-100 series, so you empty it less often, and it mounts to a wall or a surface. If your problem is checks rather than keys, the wide-and-shallow SDB-250 beats the tall SDB-106.

SDL-500: the payment box for a real volume

At 13-1/2 by 15 by 11-1/4 outside, heavy steel, the SDL-500 is for places where the drop never stops: apartment complexes with 100 or more units, church donation boxes, utility payment offices, per the listing. A wide slot takes thick stacks. If you find yourself emptying a smaller box every other day, this is the answer. The listing does not give inside dimensions, so if capacity is critical, ask us.

Match the box to the job

Four quick cases from the kind of calls we take:

• Apartment maintenance office, key returns. The SDB-100. Small, cheap, bolted behind the counter.
• Dealership or pharmacy, after-hours envelopes. The SDB-101. The wider slot is the whole point.
• Property office, monthly rent checks. The SDB-250. Flat checks, room to wait a few days between emptying.
• Church or utility office with steady traffic. The SDL-500. Buy the capacity once rather than empty a small box daily.

If you are torn between two sizes, buy the larger. A box that is too big costs you a little wall space. A box that is too small costs you jammed deposits and a person standing there with a stuck envelope.

Mounting: where drop boxes go wrong

• Stud bay. The product pages say it plainly: on a wall unit, the stud bay and wall thickness decide the job, not the box. Measure before you cut.
• Anchor into something. A steel box on drywall anchors alone invites a pry bar. Hit studs or masonry.
• Height. Put the slot where a person can drop without reaching, and where a camera sees it. A drop box nobody can watch is a drop box people try to defeat.

Shipping

Because of weight and size these ship by freight carrier and do not qualify for free shipping; the exact cost is calculated at checkout, and we will quote it first if you call (877) 365-5625.

Questions we get

Which box is the safest?

These are drop boxes, not rated safes. They keep a deposit away from the next person who walks by. For cash that a thief might attack with tools, see the depository safes in the AMSEC BWB3020 guide.

Can I keep the same key for all my boxes?

I do not have keyed-alike information for these models on the listing. Ask before you order several.

What about through-the-wall mounting?

That is a different job with different boxes, because the wall thickness has to be matched. Call us with the wall build-up and we will point you to the right model.