(defun c:PEX (/ distinct setExplodable ss opt i lst)
  
  (defun distinct (l)
    (if l
      (cons (car l) (distinct (vl-remove (car l) l)))
    )
  )
  
  (defun setExplodable (name opt / btr)
    (setq btr (entget (cdr (assoc 330 (entget (tblobjname "block" name))))))
    (entmod (subst (cons 280 opt) (assoc 280 btr) btr))
  )
  
  (if (setq ss (ssget '((0 . "INSERT"))))
    (progn
      (initget 1 "Yes No")
      (setq opt (if (= (getkword "\nSet explodable [Yes/No]: ") "Yes")
                  1
                  0
                )
      )
      (repeat (setq i (sslength ss))
        (setq lst (cons (cdr (assoc 2 (entget (ssname ss (setq i (1- i)))))) lst))
      )
      (foreach n (distinct lst)
        (setExplodable n opt)
      )
    )
  )
  (princ)
)