The robbery happened on January 6 at Cellular Express & Repairs located on the 1800 block of Washington Avenue.
Surveillance shows the suspects walking into the store at 2:15 p.m. with hoods covering their faces.
One suspect pulled a handgun and demanded cash from the register.
The pair then forced the clerk into the back office and told him to open the safe.
They ordered him to stay on the office floor while they took turns going back into the store to steal various items, including several iPhones from a display case.
The thieves were last seen running east on Washington Avenue and then north on 18th Street.
Police describe the first suspect as a black male, 20-25 years-old, 5'8"-5'10" tall. He was wearing a black sweat suit, black hooded sweatshirt, grey and white camouflage sneakers - possibly Nike Foams - and armed a handgun.
The second suspect is described as a black male, 20-25 years-old, 5'8"-5'10" tall. He was wearing a dark colored jean jacket, black hooded sweatshirt and grey sweatpants.
Anyone with information should call police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).
All tips will remain confidential.
VIDEO: Click here to watch the surveillance video