Will this hold a streamlight TR-L 1?

I'm not sure and I would be willing to say no. Because with surefire lights, they have a hinder that just clips on to the weapon. Streamlight has the nut you have to tighten. So unless you want to keep it loose on the belt clip (which might unclip under extrem conditions). This might not be what you are looking for, unless you do go with a surefire tac light.

Color	Black
Brand	Uncle Mike's
Item Dimensions LxWxH	3.7 x 2 x 1.7 inches
Item Weight	0.05 Pounds
Number Of Pockets	1
Pocket Description	Slip Pocket
Item Package Dimensions L x W x H	5.31 x 4.37 x 1.38 inches
Package Weight	0.04 Kilograms
Brand Name	Uncle Mike's
Country of Origin	Philippines
Warranty Description	One Year Limited (Materials & Workmanship)
Model Name	Kydex Clip-On Tactical Light Holder
Suggested Users	unisex-adult
Number of Items	1
Manufacturer	Uncle Mikes?s Tactical
Part Number	50301
Style	Tactical Light Holder Kydex Black Clip On, M3, M6, Glock, Clam
Included Components	Tactical Light Holder Kydex Black Clip On, M3, M6, Glock, Clam
Size	One Size
Sport Type	Hunting

Uncle Mike's Kydex Off-Duty and Concealment Clip On Accessory Tactical Light Holder, Black for M3, M6, Glock

Description

Specifications

Common Questions