None Custom/ Cutout Tiny Small Medium Large Extra Large
Sight Modifiable 1x 1u 2u 3u 4u 5u
Under-barrel N/A N/A 1u 2u 3u 4u 5u
Left N/A N/A 1u 2u 3u 4u 5u
Right N/A N/A 1u 2u 3u 4u 5u
Tactical N/A N/A 1u 2u 3u 4u 5u
Muzzle Modifiable 1x N/A N/A N/A N/A N/A
Stock Modifiable 1x 1x 1x 1x 1x N/A

“u” is the size of an attachment in units. Not necessarily an explicit length measure.

Tiny attachments are very small aiming devices such as a Kobra sight or Mini sight. The EOTech XPS2 also falls under this category. Tiny could also be pistol gun lights and lasers.

Small attachments are medium-sized aiming devices and small scopes such as the z-point, EOTech 552, Comp Aimpoint, ACOG, and PK-A. They could also be vertical type grips or IR laser combos.

Medium attachments are medium-sized scopes such as the Leupold M8-2x, VCOG 6x Scope, and TA33 ACOG. They could also be horizontal type grips.

Large attachments are full power scopes such as the PM II, Leupold M8-6x, and NXS 5.5-22. Large attachments may also include underslung weapons.

“x” is a custom